Ultrasound transducer apparatus and ultrasound imaging system and imaging method

Abstract

An ultrasound transducer apparatus includes an ultrasound transducer array consisting of multiple ultrasound transducer elements. The ultrasound transducer array is adapted for receiving and transmitting an ultrasound wave. A pulse controller is adapted for outputting multiple pulse signals to control the ultrasound transducer elements, respectively. By delaying output of the pulse signals, a plane wavefront of a transmitted ultrasound is controlled to have a different propagation direction. The pulse controller is able to activate part of the ultrasound transducer elements, corresponding to a region of interest for ultrasound wave receiving and transmitting.

What is claimed is: 
     
         1 . An ultrasound transducer apparatus comprising:
 an ultrasound transducer array comprising a plurality of ultrasound transducer elements, the ultrasound transducer array for receiving and transmitting an ultrasound wave;   a pulse controller, outputting a plurality of pulse signals to control the ultrasound transducer elements, respectively, wherein the pulse signals are controlled to output by a delay setting, and a plane wavefront of the transmitted ultrasound wave is controlled according to the delay setting to have a different propagation direction,   wherein the pulse controller is able to activate a part of the ultrasound transducer array corresponding to a region of interest for ultrasound wave transmitting and receiving.   
     
     
         2 . An ultrasound imaging system comprising:
 an ultrasound transducer array comprising a plurality of ultrasound transducer elements, wherein the ultrasound transducer elements of the ultrasound transducer array can be activated a part of the ultrasound transducer elements or a part of the ultrasound transducer elements activated is selected, according to an aperture needed by a region of interest, and the ultrasound transducer array receives a plurality of reflected waves with different wavefront angles for transforming into a plurality of electrical signals;   a pre-image processing unit, to receive and process the electrical signals to process into a plurality of corresponding digital sub-images; and   a post-image processing unit, for correcting phase and demodulating the digital sub-images and further compounding the digital sub-images into an ultrasound image.   
     
     
         3 . The ultrasound imaging system according to  claim 2 , further comprising a pulse controller adapted for outputting a plurality of pulse signals to control the ultrasound transducer elements, respectively, wherein, an ultrasound wave is transmitted according to a delay setting with the pulse signals such that a plane wavefront of the ultrasound wave is controlled to have a different propagation direction,
 wherein the pulse controller is able to activate the part of the ultrasound transducer elements corresponding to the region of interest, and the part of the ultrasound transducer elements receive and transmit ultrasound waves with respect to the region of interest.   
     
     
         4 . The ultrasound imaging system according to  claim 2 , wherein the pre-image processing unit comprises:
 a channel data unit receiving the electrical signals transformed by the ultrasound transducer array corresponding to the reflected waves;   a pre-processing unit amplifying and filtering noises from the electrical signals to obtain a plurality of groups of pre-amplified signals; and   an analog to digital converter to receive and convert the groups of pre-amplified signals into the digital sub-images.   
     
     
         5 . The ultrasound imaging system according to  claim 2 , wherein the post-image processing unit comprises:
 an interpolation and fast Fourier transform unit performing sampling-interpolation to the digital sub-images and fast Fourier transforming the digital sub-images into a plurality of frequency-domain digital sub-images;   a phase correction unit receiving the frequency-domain digital sub-images for phase correction;   an inverse fast Fourier transform unit transforming the corrected frequency-domain digital sub-images into a plurality of images in a time-domain;   a demodulation unit demodulating the time-domain images and removing baseband data to obtain a plurality of sub-images; and   a sub-image compounding unit compounding the sub-images into an ultrasound image.   
     
     
         6 . The ultrasound imaging system according to  claim 5 , wherein the interpolation and fast Fourier transform unit comprises:
 an interpolation unit performing sampling interpolation for up-sampling in a time-domain; and   a two dimensional fast Fourier transform unit performing a time-domain to frequency-domain transformation to a data matrix generated by the interpolation unit to obtain the frequency-domain sub-images.   
     
     
         7 . The ultrasound imaging system according to  claim 5 , wherein the interpolation and fast Fourier transform unit comprises:
 a two dimensional fast Fourier transform unit performing a time-domain to frequency-domain transformation to the digital sub-images to obtain the frequency-domain sub-images; and   an interpolation unit performing sampling interpolation for up-sampling the frequency-domain sub-images to increase sampling points.   
     
     
         8 . The ultrasound imaging system according to  claim 2 , wherein the number of the reflected waves is an odd number comprising a reflected wave with a zero degree wavefront and at least a pair of reflected waves with symmetrical positive and negative wavefront angles. 
     
     
         9 . The ultrasound imaging system according to  claim 2 , further comprising a region of interest correlation processing unit, wherein the ultrasound image obtained by the ultrasound transducer array at the first time is a first ultrasound image, the ultrasound transducer elements are all activated, and the region of interest is determined from the first ultrasound image to control the ultrasound transducer array to activate the part of the ultrasound transducer elements or select the part of the ultrasound transducer elements activated, according to the aperture needed by the region of interest to obtain a second ultrasound image,
 wherein a correlation calculation is performed between the first ultrasound image and the second ultrasound image with respect to the region of interest to obtain a third ultrasound image, and a further correlation calculation is performed between the second ultrasound image and the third ultrasound image to obtain a fourth ultrasound image.   
     
     
         10 . The ultrasound imaging system according to  claim 2 , further comprising a region of interest correlation processing unit, wherein the ultrasound image obtained by the ultrasound transducer array at the first time is a first ultrasound image, the ultrasound transducer elements are all activated, and the region of interest is determined from the first ultrasound image to control the ultrasound transducer array to activate the part of the ultrasound transducer elements or select the part of the ultrasound transducer elements activated, according to the aperture needed by the region of interest to obtain a second ultrasound image,
 wherein a correlation calculation is performed between a directly continuously measured fifth ultrasound image and the second ultrasound image to obtain a sixth ultrasound image.   
     
     
         11 . An ultrasound imaging method comprising:
 providing an ultrasound transducer array, wherein the ultrasound transducer array comprises a plurality of ultrasound transducer elements, the ultrasound transducer array is able to activate part of the ultrasound transducer elements or select part of the ultrasound transducer elements activated, according to an aperture needed by a region of interest, and the ultrasound transducer array receives a plurality of reflected waves with different wavefront angles for transforming into a plurality of electrical signals;   performing a first ultrasound imaging, comprising:   activating all the ultrasound transducer elements and receiving a reflected wave with a zero degree wavefront and a pair of reflected waves with non-zero degree wavefronts that are reflected back by a detection target, the non-zero degree wavefronts having symmetrical positive and negative wavefront angles;   performing a pre-image processing for receiving the electrical signals transmitted from the ultrasound transducer array and processing the electrical signals into a plurality of digital sub-images; and   performing a post-image processing for phase correcting and demodulating the digital sub-images and further compounding the digital sub-images to obtain a first ultrasound image, wherein the region of interest is determined from the first ultrasound image;   performing a second ultrasound imaging, comprising:   activating the part of the ultrasound transducer elements or select the part of the ultrasound transducer elements activated according to the aperture needed by the region of interest, repeating the receiving of the reflected wave with a zero degree wavefront and the pair of reflected waves with non-zero degree wavefronts that are reflected back by the detection target, the non-zero degree wavefronts having symmetrical positive and negative wavefront angles;   repeating the pre-image processing; and   repeating the post-image processing to obtain a second ultrasound image with respect to the region of interest; and   performing a correlation calculation between the first ultrasound image and the second ultrasound image with respect to the region of interest to obtain a third ultrasound image, and further performing a correlation calculation between the second ultrasound image and the third ultrasound image to obtain a fourth ultrasound image.   
     
     
         12 . The ultrasound imaging method according to  claim 11 , wherein the pre-image processing comprises:
 receiving the electrical signals transformed by the ultrasound transducer array corresponding to the reflected waves;   amplifying and filtering noises from the electrical signals to obtain a plurality of groups of pre-amplified signals; and   receiving the groups of pre-amplified signals to convert into the digital sub-images.   
     
     
         13 . The ultrasound imaging system according to  claim 11 , wherein the post-image processing comprises:
 performing an interpolation and fast Fourier transform for sampling-interpolation to the digital sub-images and fast Fourier transforming the digital sub-images into a plurality of frequency-domain digital sub-images;   phase correcting the frequency-domain digital sub-images;   transforming the corrected frequency-domain digital sub-images into a plurality of images in a time-domain;   demodulating the time-domain images and removing baseband data to obtain a plurality of sub-images; and   compounding the sub-images into the first ultrasound image or the second ultrasound image.   
     
     
         14 . The ultrasound imaging system according to  claim 13 , wherein the interpolation and fast Fourier transform comprises:
 performing sampling interpolation for up-sampling in a time-domain; and   performing a time-domain to frequency-domain transformation on a data matrix generated by the interpolation unit to obtain the frequency-domain sub-images.   
     
     
         15 . The ultrasound imaging system according to  claim 13 , wherein the interpolation and fast Fourier transform comprises:
 performing a time-domain to frequency-domain transform to the digital sub-images to obtain the frequency-domain sub-images; and   performing sampling interpolation for up-sampling the frequency-domain sub-images.